Modern computer networks employ a variety of safeguards against undesirable transmission. Commonplace media coverage of identity theft, breaches divulging sensitive information such as credit card numbers, and spyware that parasitically embezzles part or all of a host CPU for unauthorized usage, all underscore the need for network protection. Such network protection typically takes the form of intrusion detection measures deployed at strategic points in the network, and on the actual computer systems that may harbor such undesirable programs, typically called malware.
Security mechanisms for defending networks against malicious cyber attacks must evolve along with the emergence of new attacks and the development of new communication technologies that form the network. Early attacks destroyed data, disabled hosts, or disrupted portions of the network. These were brute force and reasonably easy to detect. Modern attacks are subtler, and serve a growing economy of stolen personal, commercial, or nationally held information. High speed switching fabrics and transmission technologies, and new protocols supporting a vast array of powerful applications, mean that cyber attacks have many new vectors of penetration, and traditional signature-based and anomaly detection-based defensive measures are simply inadequate in both speed and function.